Food Packaging: Can or pouch, it's all about ease of use

Retortable containers need an influx of innovation if they're going to keep up with the convenience trend.

Easy to follow directions guide users of the dot top, a can end with the attributes of a jar cap. Source: Silgan.

If ink could be used to package food, metal containers would be a vanishing breed. Most packaging-news ink, after all, is about plastic containers.

Much of that ink is fueled by a steady diet of innovation. Ampac Packaging LLC, a Cincinnati supplier of film, is set to begin producing multilayer films for microwaveable retort pouches. It's another watershed in the march toward greater consumer convenience, according to product manager Chad Buckley of Ampac.

Saran film is extruded at Ampac's plant in Cincinnati. Source: Ampac.

The co-extruded film uses Saran as a substitute for foil, EVOH and PET coated with aluminum oxide, opening the way for re-heating in America's preferred cooking appliance.

Ampac's innovation is the kind of event that used to make can makers cringe. Times are changing, though, and sometime in the new year Ball Corp. is expected to rollout the microwavable can or, more accurately, a bowl with rounded edges that can be heated without sending sparks flying.

"In terms of line efficiency, filling speeds and the fact that canning equipment is already paid for and in place, can technology enjoys an economic advantage over flexible pouches and other packaging forms," observes Ron Thomas, chairman of the packaging department at Clemson University. "But today's food packaging isn't just a matter of simple engineering principles. Aesthetics, convenience and function have value. If a can delivers, the consumer isn't going to worry about a small upcharge for superior packaging."

Can manufacturers have reached the same conclusion. "Beginning in 1999, we shifted from a focus on cost reduction and started to look at ways to improve consumer utility," says Bill Clancy, national accounts manager for Silgan Containers Corp.

The easy-open end took off when Campbell soup converted to pull-tabs and saw a double-digit spurt in volume sales. The dot-top is still new technology in North America, though it has a successful nine-year track record in the southern hemisphere. Silgan licensed the technology and guided January's conversion of a can line at Toledo-based Hirzel Canning Co., replacing a double-seemer with a capper that handles 400 cans a minute.

Steam is injected as the lid is placed on a can, creating a vacuum that later is released when the consumer vents the can by lifting the dot. Overpressure is required during processing. The lid is resealable, and the elimination of sharp edges is a plus with children's meals.

Saturated steam retorts lack overpressure and have slowed both metal and plastic package innovations, Clancy maintains. Besides dot tops and microwaveable pouches, foil ends for cans also require overpressure, and that has limited applications to dry foods. Silgan expects to overcome the limitation with a Generation III foil end that can withstand conventional retort processing, Clancy says.

By then, the microwaveable retort pouch should be well established, Ampac's Buckley predicts. The company will begin extruding high-barrier, 8-16 layer films containing Dow Chemical's Saran resins in February, he says. "Doubling up the Saran layers gives you some unique properties, including added strength and added barrier protection against oxygen and moisture."

High speed, complex motion and logic are managed by a single controller for this two-piece cardboard converter of open-basket carriers from Roberts PolyPro. Source: Rockwell Automation.

High speed meets high tech

Ray Neel isn't old, but his machine-control career bridges the mechanical-to-integrated-controls gap.

Neel is controls engineering manager at Roberts PolyPro, a Charlotte, NC, OEM that builds packaging machines for copackers and package converters. They are big, high-speed units and the mechanical versions consisted of "one big, honkin' motor and all these gears," he recalls.

Changeovers tended to be workday nightmares for users. Re-timing servos with the push of a button is an operator's dream.

The more complicated the machine, the more valuable the transition to superior controls technology. An example is a two-piece cardboard open-basket carrier built by Roberts PolyPro. The system stretches 60 to 80 feet and administers 40 shots of glue as it marries a six-pack carrier to another piece of cardboard with graphics. Bottled water suppliers, soft drink companies and breweries are the primary users of the machines, which output more than 400 pieces a minute.

The first new-generation machine built by Roberts relied on an Allen-Bradley SLC 5/04 for logic control and Indramat motion controls at the drive level. The latest machine, a 22-axis unit built for Heineken and capable of converting 500 pieces a minute, features A-B's ControlLogix programmed with RSLogix software for combined motion and logic control. Neel also made use of Visual Basic for Applications to slash engineering and debugging time by incorporating reusable code in the application.

"The biggest benefit for end-users is simplicity," explains Neel. "With one processor, if you ever have a problem, you know where it is," and that translates to less downtime.

For more information:

Bron Dodds, Rockwell Automation, 704-559-5344

Home bakers who put their measuring cups away because of carbohydrate concerns and the poor baking properties of artificial sweeteners now have a new option: Sugar Lite from Equal, a blend of large-crystal sugar and Equal no-calorie sweetener. Peel Plastics, Brampton, ON, developed the package.

Hybrid sweetener stands up for bakers

Sugar does more than sweeten baked goods: it also browns and adds volume to them. Unfortunately, sugar also adds carbohydrates and calories, and that is a sweets-making disincentive for diet-conscious home bakers. A solution is Sugar Light from Equal, a mixture of the no-calorie artificial sweetener Equal and coarsely ground sugar crystals.

A product of Merisant Worldwide Inc., Sugar Lite from Equal debuted on grocers' shelves in August, in a laminated PET/polyethylene standup pouch. "It definitely has more shelf pop and impact" than conventional sweetener packaging, believes Susan Evans, manager of packaging development at Chicago-based Merisant.

The product was developed in Europe, where its lower-calorie formulation and cup-for-cup measurement equivalence made it a hit. North America's fascination with low-carb diets made the product a logical fit here. Once a go decision was reached, Evans oversaw a rapid ramp-up.

Peel Plastic Products Ltd. developed two sizes of bags with reclosable zippers in its Toronto-area plant. The 500-gram package measures 7.5 inches wide, 9 inches tall and 2.5 inches deep. The volume is equivalent to 2 lbs. of sugar, though only half the weight. Sugar Lite also comes in a 1,000-gram package.

Merisant's contract manufacturer for Sugar Lite uses a rotary-head filling machine from PSG Lee of Korea to fill the pre-made bags. Until the mid-1990s, hand filling often was required with these types of pouches. With the automated system, bags are loaded in a magazine, then opened, filled and sealed automatically, according to Peel's Andrew Proctor. The machines typically fill about 35 bags per minute.